1. Field of the Invention
The present invention relates to an information retrieval apparatus capable of retrieving a document being in accord with a user's intention of retrieval and a recording medium having an information retrieval program recorded in it.
2. Description of Related Art
In recent years, necessary information is often retrieved and utilized by using an information retrieval service on the World Wide Web (WWW). However, since an information retrieval service being generally performed on WWW requires an information retrieval request represented by a combination of keywords, a beginner being unfamiliar with a computer cannot properly represent a combination of keywords for exactly representing the desired information, and therefore has difficulty in exactly retrieving the desired information. As a conventional technique for performing an exact information retrieval by extracting a retriever's intention in consideration of such a problem, there is an information retrieval apparatus disclosed in Japanese Patent Laid-Open Publication No. Hei 7-105,233 (hereinafter referred to as literature 1). The information retrieval apparatus disclosed in literature 1 extracts a retriever's intention by means of interaction between the retriever and the apparatus using a natural language in order to perform an exact retrieval. The said information retrieval apparatus infers an inexplicit idiomatic expression or an abbreviated word being liable to be used in a natural language from the context of this interaction, and produces a retrieval request meeting the retriever's intention.
By the way, WWW has WWW pages each containing a collection of link destinations of a certain kind of information. A user can obtain a great amount of related information at a time by browsing these WWW pages, but since such pages are often made by gathering and arranging various formation by hand, it is difficult to cover all the related information. Therefore, in case of desiring further information, a user needs to move to a page for retrieval and perform retrieval in consideration of its retrieval conditions. It is conceivable also to make a page for retrieval using the information retrieval apparatus disclosed in literature 1, but in such a case even if an inexplicit idiomatic expression or an abbreviated word is allowable, eventually a retriever results in being forced to input a natural language and in bearing a burden equivalent to or heavier than inputting keywords. And it is necessary to analyze in advance a document straightforwardly representing the content of a document to be retrieved and additionally it is necessary to prepare a concept dictionary at the information retrieval apparatus side, and therefore construction of such an apparatus requires such a great cost that it is not practical.